The study of memory and executive dysfunction in patients infected with Helicobacter pylori.

Background Infectious agents are considered as potential causes of Alzheimer's disease. Recently, evidence of a high prevalence of Helicobacter pylori (H. pylori) infection in patients with Alzheimer's disease has been observed. The aim of this study was to investigate memory and executive function in H. pylori positive persons not suffering from Alzheimer's or other marked cognitive disorders. Methods This is a cross-sectional study. A total 140 participants were selected using purposive sampling from the patients within the age group of 18-60 years old at Fayyaz Bakhsh Hospital, Tehran in spring 2016. The participants were divided into two groups of H. pylori positive and negative according to results of the serologic tests to measure the levels of specific antibodies of IgA and IgG against H. pylori using ELISA method. They were subsequently assessed using two tests of Trail Making (TMT) part A and B and Wechsler Memory Scale - Third Edition. Data were analyzed using independent t-test and chi-square. The level of significance was considered P-value ≤ 0.05. Results Out of 140 participants, there were 41 male (29.3%) and 99 female (70.7%) among which 84 patients (60%) suffered from H. pylori infection (seropositive) and 56 patients (40%) were not infected. Comparison of the results using independent t-test showed a significant difference (P = 0.006) between the memory scores of patients (M: 106, SD: 8.12) and healthy ones (M: 112, SD: 1.12). In addition, the executive function showed there is a significant difference in the executive ability of seropositive individuals in the two age groups of 20-50 years old (Part A: M: 1.36, SD: 7.11, and Part B: M: 8.8, SD: 8.25 p = 0.01) and over 50 years old (Part A: M: 55, SD: 8.20, and Part B: M: 106, SD: 7.22, p = 0.009). Conclusion The results of this study showed that the infected patients have a lower cognitive performance in comparison to healthy individuals. In other words, H. pylori infection increases the prevalence of memory and executive dysfunction.